(Azir) Emperor's Divide lag

I am an avid ARAM player, as such in many of my games as Azir I have found that when I go to cast my (R) Emperor's Divide, there is a 1-2 second delay between the activation (highlight of the ability in game with the keystroke) and the actual animation and resulting ability triggering. This is not attributed to lag my ping is generally 25-80(max), as well every other ability does not lag in the same fashion. If this is an actual mechanic of the skill then the tool tip needs to be updated please.

Thank you for your time.